The present invention is in the field of exterior aircraft lighting. More particularly, the present invention is concerned with those exterior aircraft light units that illuminate the aircraft itself.
Exterior aircraft lighting serves a wide range of purposes. On the one hand, there is safety-critical lighting, such as position signalling and take-off/landing lighting. On the other hand, certain lights are provided for marketing purposes. An example of such a light is a fin illumination light, illuminating the vertical structure at the tail of the plane, which is usually provided with the airline's logo.
Modern airplanes increasingly have so-called winglets at the ends of their wings. These winglets are wing tip structures that are angled with respect to the wing profile and extend generally upwards. On the one hand, such winglets reduce lift induced drag caused by wing tip vortices. On the other hand, such winglets also provide an area of the aircraft for advertising and logo placement, with the inward-facing side of the winglets being visible to the passengers within the airplane.
It is generally desirable to improve the visibility of the winglet surfaces in poorly lit conditions, such as during night flights. However, no efficient technology for illuminating the winglets has been provided to date. Accordingly, it would be beneficial to provide illumination of the winglets in an efficient manner.